Fix incorrect sys.argv[0] path when calling project scripts

src/poetry/console/commands/run.py

@@ -5,6 +5,7 @@
 from cleo.helpers import argument
 
 from poetry.console.commands.env_command import EnvCommand
+from poetry.utils._compat import WINDOWS
 
 
 if TYPE_CHECKING:
@@ -44,7 +45,25 @@ def _module(self) -> Module:
 
         return module
 
-    def run_script(self, script: str | dict[str, str], args: str) -> int:
+    def run_script(self, script: str | dict[str, str], args: list[str]) -> int:
+        """Runs an entry point script defined in the section ``[tool.poetry.scripts]``.
+
+        When a script exists in the venv bin folder, i.e. after ``poetry install``,
+        then ``sys.argv[0]`` must be set to the full path of the executable, so
+        ``poetry run foo`` and ``poetry shell``, ``foo`` have the same ``sys.argv[0]``
+        that points to the full path.
+
+        Otherwise (when an entry point script does not exist), ``sys.argv[0]`` is the
+        script name only, i.e. ``poetry run foo`` has ``sys.argv == ['foo']``.
+        """
+        for script_dir in self.env.script_dirs:
+            script_path = script_dir / args[0]
+            if WINDOWS:
+                script_path = script_path.with_suffix(".cmd")
+            if script_path.exists():
+                args = [str(script_path), *args[1:]]
+                break
+
         if isinstance(script, dict):
             script = script["callable"]
 

tests/console/commands/test_run.py

@@ -146,3 +146,40 @@ def test_run_script_exit_code(
     )
     assert tester.execute("exit-code") == 42
     assert tester.execute("return-code") == 42
+
+
+@pytest.mark.parametrize(
+    "installed_script", [False, True], ids=["not installed", "installed"]
+)
+def test_run_script_sys_argv0(
+    installed_script: bool,
+    poetry_with_scripts: Poetry,
+    command_tester_factory: CommandTesterFactory,
+    tmp_venv: VirtualEnv,
+    mocker: MockerFixture,
+) -> None:
+    """
+    If RunCommand calls an installed script defined in pyproject.toml,
+    sys.argv[0] must be set to the full path of the script.
+    """
+    mocker.patch("poetry.utils.env.EnvManager.get", return_value=tmp_venv)
+    mocker.patch(
+        "os.execvpe",
+        lambda file, args, env: subprocess.call([file] + args[1:], env=env),
+    )
+
+    install_tester = command_tester_factory(
+        "install",
+        poetry=poetry_with_scripts,
+        environment=tmp_venv,
+    )
+    assert install_tester.execute() == 0
+    if not installed_script:
+        for path in tmp_venv.script_dirs[0].glob("check-argv0*"):
+            path.unlink()
+
+    tester = command_tester_factory(
+        "run", poetry=poetry_with_scripts, environment=tmp_venv
+    )
+    argv1 = "absolute" if installed_script else "relative"
+    assert tester.execute(f"check-argv0 {argv1}") == 0

tests/fixtures/scripts/pyproject.toml

@@ -9,6 +9,7 @@ readme = "README.md"
 python = "^3.7"
 
 [tool.poetry.scripts]
+check-argv0 = "scripts.check_argv0:main"
 exit-code = "scripts.exit_code:main"
 return-code = "scripts.return_code:main"
 

tests/fixtures/scripts/scripts/check_argv0.py

@@ -0,0 +1,23 @@
+from __future__ import annotations
+
+import sys
+
+from pathlib import Path
+
+
+def main() -> int:
+    path = Path(sys.argv[0])
+    if sys.argv[1] == "absolute":
+        if not path.is_absolute():
+            raise RuntimeError(f"sys.argv[0] is not an absolute path: {path}")
+        if not path.exists():
+            raise RuntimeError(f"sys.argv[0] does not exist: {path}")
+    else:
+        if path.is_absolute():
+            raise RuntimeError(f"sys.argv[0] is an absolute path: {path}")
+
+    return 0
+
+
+if __name__ == "__main__":
+    raise sys.exit(main())